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BGP filter to allow only default route

My router is peering with my MPLS ISP CE router. I am running OSPF in my internal network and EBGP with my ISP. I want my ISP to advertise his default route via BGP to my router. I will then redistribute his default route via OSPF to my internal network.

My ISP MPLS CE router has a default route IP ROUTE 0.0.0.0 0.0.0.0 nxt_hop_ip. They have REDISTRIBUTE STATIC in his BGP process. I did not test this yet, but will this work as how to advertise the default route to my router? Or does he need to have NETWORK 0.0.0.0 MASK 0.0.0.0 in his BGP process.

Also, I'd like to redistribute just his BGP default route to my OSPF. It looks like, in my BGP to OSPF redistribution, I have to filter out all his BGP routes and only except the default route. How do I do that? Thanks

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mikebernhardt

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leblanc

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My ISP sends all the BGP routes to my router so I have to filter to allow just the default route. I got the config below. But I am just wondering if I really need to redistribute BGP with route-map because the "default-information originate metric 100 metric-type 1" in OSPF will advertise the default route in my routing table (which is the one advertised by BGP. Any thought? Thx

router ospf 1
router-id 10.2.255.1
network 10.2.0.0 0.0.255.255 area 0
redistribute bgp 65001 metric 100 metric-type 1 subnets route-map BGP_DEFAULT_ROUTE
default-information originate metric 100 metric-type 1
!
router bgp 65001
bgp router-id 1.1.1.1
bgp log-neighbor-changes
neighbor 10.200.125.1 remote-as 65002
network 10.200.0.0 mask 255.255.0.0
redistribute ospf 1
!
ip prefix-list BGP_DEFAULT_ACL seq 5 permit 0.0.0.0/0
!
ip prefix-list BGP_DEFAULT_ROUTE permit 10
match ip address prefix-list BGP_DEFAULT_ACL

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mikebernhardt

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